Special Contribution Nobel Minds Expand Our Universe

Robert Quimby IPMU Postdoctoral Fellow

There had been considerable interesting research being conducted, star near its critical mass limit as speculation that he would eventually and there were great advisers to point a necessary ingredient, then the receive the world’s most famous astray students in the right direction conformity in Type Ia supernovae can award, yet I was still pleasantly (George Smoot went on to win the simply be explained by the similar surprised on the day Saul Perlmutter 2006 Nobel Prize in Physics). quantities and distributions of fuel in won the 2011 Nobel Prize in Physics Saul’s team was using distant the explosions. Turning these stellar along with Brian Schmidt and Type Ia supernovae to derive the bombs into rulers to measure great Adam Riess for the discovery of matter density of the universe and distances is then straightforward. the accelerating expansion of the the deceleration parameter, which As with any source of light, the universe. I served on Saul’s team as was originally intended to express brightness of a supernova appears an undergraduate (and later "post- how quickly the expansion of the to decrease with the distance to the baccalaureate") from 1997 and made universe was slowing down due to observer squared. Since we know a small contribution to the prize- the con­ning pull of gravity. As the the luminosity of Type Ia, we also winning paper. Saul generously Nobel Prize was awarded for the know how distant they are to good invited the whole team to join in the acceleration in the expansion of the accuracy (about 5% with careful festivities, so last December I boarded universe, we now know that the corrections), and since they are quite a plane bound for Stockholm. value of this deceleration parameter is bright, we can see them even when My connection to this Nobel Prize negative. But this was not clear at the they are extremely far away. The winning research began when I was time as režected in this unfortunate light from the most distant Type Ia at Berkeley looking for some research name. supernovae discovered came from so experience to ­ll out my future The key to using Type Ia far away that it takes about 10 billion graduate school applications. Not supernovae as cosmological probes years to reach earth. The universe has sure of what to do, I sent out a blind comes from empirical evidence that expanded greatly since these stars email solicitation. Ok, I spammed the different Type Ia supernovae all have exploded, and this effects the photons physics department. Luckily, I got one about the same peak luminosity. This on their journey to earth as well so reply from "George" who didn’t have may be attributed theoretically to that short wavelength blue light get a job for me but knew someone who physical laws that limit how much stretched into red. The extent of this might. Saul Perlmutter was leading mass white dwarfs, the dying embers "redshift" conveys the accumulated a project that involved supernovae, of stars similar to our Sun, can steal effects of this expansion since the which seemed a good match given from a companion and remain stable. light escaped from these exploding my astrophysics major. This was one There is still debate about the exact stars. By measuring the redshifts to of the great advantages of studying nature of these progenitor systems, Type Ia supernovae over a range of at UC Berkeley; there was plenty of but if one considers a white dwarf distances, Saul hoped to map out

4 IPMU News No. 17 March 2012 The Supernova Cosmology Project members in Stockholm during Nobel Week. Back row: Ivan Small, Sebastian Fabbro, Greg Aldering, Robert Quimby, Brad Schaefer, Rob Knop, Renald Pain, Carl Pennypacker, Shane Burns, Richard Muller, Ariel Goobar, Peter Nugent. Front row: Alex Kim, Pilar Ruiz-Lapuente, Andy Fruchter, Nelson Nunes (middle), Richard Ellis, Julia Lee, Susana Deustua, Saul Perlmutter, Warrick Couch, Heidi Newberg, Sylvia Gabi, Chris Lidman, Don Groom.

the universe’s expansion history and telescope a month later, there will were on stage regaling a packed determine just how much gravity was be a dozen new Type Ia supernovae auditorium with the tale of their slowing down the expansion of the waiting to be found. As Saul discovery. Brian recounted how he universe. At least that was the original explained during his Nobel Lecture had read one of the ­rst telegrams plan. in the magni­cent Aula Manga put out by Saul’s team, the Supernova Saul invented a novel technique to lecture hall of Stockholm University, Cosmology Project, to announce the discover distant Type Ia supernovae the tough part was convincing the successful discovery of a batch of in batches, on demand. A galaxy telescope allocation committees that high redshift supernovae and decided such as our own Milky Way has, on this would work and to schedule the to start a competing team leveraging average, just one Type Ia supernova observing runs as needed. It was not his group’s expertise using Type Ia every 200 years. It is therefore enough for Saul to invent the strategy supernovae as distance indicators. Special impractical to discover supernovae to ­nd cosmologically interesting Brian invited Adam to join, and the Contribution in any particular galaxy within the supernovae; he needed the tenacity to High-z Search Team was born. As lifetime of a typical research grant. see it carried out despite formidable you might imagine, the competition However, if you look in any direction opposition. for resources and to publish ­rst at a patch of sky roughly the size of The Lectures are one of the ­rst fomented a certain amount of the full moon, there are thousands events in what is known as Nobel animosity in the early days, but this of distant galaxies churning out Type Week. It was also the moment that has faded away over the years. Ia supernovae. Take a deep enough I began to realize that this was real The highlight of Nobel Week is of exposure of a few such patches, and – Brian, Adam, and Saul had really course the award ceremony, which when you revisit the ­elds with your won the Nobel prize, and there they is followed by a banquet, dancing,

5 and then more dancing. This all entered the theater. The orchestra to your left and bow to the Nobel begins the anniversary of Alfred played Mozart as the winners of Academy on stage, and 6) turn to Nobel's birth, December 10, with the physics, chemistry, medicine face the audience, bow, and bask in the celebration running well past economics, and literature prizes your ovation. When the applause die midnight. The laureates are each marched in. This was not the most down, you may return to your seat, given complimentary tickets to share common of venues for an astronomer but don't open boxes! They will be with their families and collaborators, like myself who is more familiar with collected after the ceremony and the but the standard allocation is not jeans and tee-shirts than tuxedos and contents displayed for 2 days before enough to accommodate all the co- waist coats, and the fact that much they are returned to you for good. authors on such modern, highly of the ceremony is done in Swedish Saul appeared slightly nervous as collaborative experiments. An equal did not help me to feel at home he walked to the King, and it was number is given to each awardee, either. But it was absolutely amazing, reassuring to see that he and the so the High-z Team started off with nonetheless, to see Saul honored other laureates retained their humility twice the number of seats as the on stage at this most prestigious in spite of the pampering heaped Supernova Cosmology Project, which ceremony. on them since the announcement evoked some grumbling amongst Saul was the ­rst laureate to of their honor. He executed the my team, echoes of the former be awarded his prize, which like next two steps with precision, but rivalry. Saul pleaded on behalf of his everything else that night was a nearly erred on the fourth step. After collaborators, and in the end all of the tightly choreographed process taking the customary two steps back, team members in Stockholm received constrained by customs far older Saul began to turn ever so slightly tickets to the ceremony (mine came than the prize itself. For the record, without bowing to the King. The just hours before the start of the the proper procedure for receiving audience let out a collective gasp. show). your Nobel Prize is: 1) stand when Saul corrected himself and bowed Dressed in our formal costumes – called upon and walk to the center to the King appropriately, much to white tie and tails for the men and of the stage, 2) receive the boxes the relief of those in attendance. The evening gowns for the women – we with your diploma and medal from near transgression lasted perhaps one observed from the balcony as the the King with two hands, 3) shake second, but it served to intensify then drums rolled and the King, Queen, the King's hand, 4) step back and break the tension in the room. and Crown Princess of Sweden bow to the King, 5) turn 45 degrees The ceremony was followed by the

The Nobel Prize Ceremony in the Stockholm Concert Hall.

6 IPMU News No. 17 March 2012 Nobel Banquet, which was held in but rather the Stockholm City Hall. Despite the accelerating. He 1300 seats in the main hall, which is rushed to my of­ce a voluminous room decorated to give on the day the the feeling of being outdoors, tickets results came in, and were again in short supply for the two I reported that with teams, and I joined the overžow in a greater than 99% separate room (the actual dining hall con­dence, the in the basement). The adjacent room expansion history of held the relatives of Alfred Nobel, the universe could and we all had the same three-course not be ­t by the meal served to the laureates and gentle attraction of royalty, complete with a pyrotechnic gravity alone. True dessert. After coffee and cognac, two to his meticulous of the six beverages served through style, Saul requested the meal, we were escorted upstairs double, triple, and to join the party. I managed to ­ght quadruple checks, through the crowds to congratulate but the results held: Saul, and he humored me when I a mysterious force is asked for a picture, as did so many pulling the universe others that night. As if this all weren't apart. enough, there was a ­nal celebration, After participating the Nobel Night Cap, thrown by in what has become University of Stockholm students. a Nobel Prize The 2011 Nobel Prize laureate, Saul Perlmutter, with the author after the The Laureates still had energy to chat winning experiment, banquet. and pose for pictures well past 3 am I attended graduate when we said our goodnights. school where I continued to study Questions about the nature of the I was invited to participate in this supernovae. This companion are just beginning to be fantastic week of celebration for time instead of looking across the addressed. providing a small but important role universe, I created my own modest During my search for ordinary in the discovery. I helped ­t models search to locate the closest Type Type Ia explosions, I uncovered the to the data to ­nd the cosmological Ia supernovae I could ­nd. I began extraordinary supernovae with peak parameters. Saul has described the to study supernovae themselves to magnitudes and energetics ten times realization of his discovery not as a help reveal exactly what they are to greater than ever seen before. Much single moment, but rather as a long help perfect the calibration of their like their lower luminosity cousins, “ah̶ha” process. My contribution peak magnitudes and turn them these superluminous supernovae may came near the end of this when it into even better distance indicators, serve as probes of the distant universe started to become clear that the which will be useful in addressing and help reveal its beginnings. Special supernovae discovered actually the obvious question remaining Whether the results will similarly defy Contribution appeared a little fainter than we after the champagne was ­nished, expectations remains to be seen. had expected given their redshifts. "what is the nature of this Dark In other words, it seemed that Energy accelerating the universe?” the universe had expanded more Amazingly, the ­rst empirical evidence than expected since these distant that Type Ia supernova are truly the supernovae exploded. Saul asked explosions of white dwarf stars was me to help determine if there was not obtained until late 2011 by the evidence that the expansion of the Palomar Transient Factory, which I universe was not slowing down at all, have contributed to as a postdoc.

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